The Unknowns of Food Irradiation

One year has passed since the nation's first food irradiation plant opened in Mulberry, Florida. With approval in hand from the Food and Drug Administration to irradiate fruits and vegetables, Vindicator Inc. sent strawberries out onto the market amidst much media debate.

Five months later, despite the hue and cry regarding nutritional effects, worker exposure, and unknown chemical reactions, the FDA also approved poultry for irradiation. But corporations such as Kraft, Conagra, Kellogg, and Kentucky Fried Chicken have paid closer attention than the FDA to consumer concern, refusing so far to irradiate their products. "We want to do it, but we want to be second," said one poultry processor. Maine, New York, and New Jersey (as well as Australia, New Zealand, Denmark, Norway, Sweden, and Germany) have put a moratorium on or have banned outright the sale of irradiated food.

The issue is tricky. Anyone who has done time in the bathroom with food poisoning will find a certain amount of appeal in the concept--exposing food to gamma rays from cobalt 60 or cesium 137, thus destroying salmonella and other bacteria. (Unfortunately, the technique does not destroy the bacteria that causes botulism.) The process does not make food radioactive.

Food irradiation is not new. Since the 1960s, the United States has used it to control insects in wheat, flour, and spices and to prevent sprouting in potatoes. Proponents point out that in some cases irradiation replaces dangerous chemicals currently used to control insects and bacteria. That is a plus.

But still unknown to scientists and government regulators is the extent to which food irradiation causes toxic chemical byproducts--such as benzene, a carcinogen. These byproducts would be created when the bombardment of the gamma rays breaks up food molecules, causing organic free radicals that then can react diabolically with other benign substances. Some people say these toxic substances occur in traces that are not harmful. Others point out that no one knows what level to call "acceptable."

Loss of nutrients is another concern. In one study, the vitamin C content of potatoes was reduced by 50 percent after the potatoes had been given a standard dose of radiation. Vitamins A, C, E, and some of the B complex are particularly vulnerable, resulting in fresh vegetables that are nutritionally more similar to canned. Another study showed a 17 percent thiamine loss in radiated pork and a 9 percent loss in chicken.

Speaking of chicken, some critics speculate that food irradiation would be used as a crutch by the poultry industry, leading to even more lax sanitary procedures in processing plants. The U.S. Agriculture Department estimates that already close to 40 percent of all raw poultry is contaminated with salmonella.

Then there is the very valid concern over the potential hazards radioactive isotopes pose to plant workers--higher than at nuclear power plants because the chambers are opened more frequently--and to people who live near the plant. Food irradiation just adds to our existing problems of nuclear waste transport and disposal.

Finally, hints of evidence that certain foods may be more vulnerable to the ravages of fungi and insects after irradiation ring true to me. Too often in the world of agriculture, so-called miracle pesticides have ruined the predator balance so that ever worse epidemics occur. Will this be another example of humans thwarting nature's long-term equilibrium?

As research and debate--and food irradiation--continue, each of us will have to decide whether or not to incur the risks. Fortunately, irradiated food must by law be labeled, although not all irradiated ingredients have to be (in sauce products, for example).

Stay tuned. As with milk pasteurization and other important food preservation technologies, food irradiation deserves to be examined. But very carefully.

Carey Burkett was an organic vegetable farmer in Hallettsville, Texas when this article appeared.